/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.myfaces.spi.impl;
  
  import javax.faces.context.ExternalContext;
  import org.apache.myfaces.shared.util.ClassUtils;
  import org.apache.myfaces.spi.InjectionProvider;
  import org.apache.myfaces.spi.InjectionProviderException;
  import org.apache.myfaces.util.ExternalSpecifications;
  
  /**
   * Delegation pattern to avoid direct instantiation
   */
  public class CDIAnnotationDelegateInjectionProvider extends InjectionProvider
  {
      private InjectionProvider delegate;
      private final boolean available;
      
      public CDIAnnotationDelegateInjectionProvider(ExternalContext externalContext)
      {
          if (ExternalSpecifications.isCDIAvailable(externalContext))
          {
              try
              {
                  Class clazz = ClassUtils.simpleClassForName(
                      "org.apache.myfaces.cdi.impl.CDIAnnotationInjectionProvider");
                  delegate = (InjectionProvider) clazz.getConstructor(
                      ExternalContext.class).newInstance(externalContext);
              }
              catch(Exception e)
              {
                  //Ignore
              }
          }
          available = (delegate != null);
      }
  
      @Override
      public Object inject(Object instance) throws InjectionProviderException
      {
          if (available)
          {
              return delegate.inject(instance);
          }
          return null;
      }
  
      @Override
      public void postConstruct(Object instance, Object creationMetaData) throws InjectionProviderException
      {
          if (available)
          {
              delegate.postConstruct(instance, creationMetaData);
          }
      }
  
      @Override
      public void preDestroy(Object instance, Object creationMetaData) throws InjectionProviderException
      {
          if (available)
          {
              delegate.preDestroy(instance, creationMetaData);
          }
      }
  
      @Override
      public boolean isAvailable()
      {
          return available;
      }
  }